A common problem is to isolate an apparatus from external sources of vibration, including building vibrations and acoustical noise such as loud talking, hand claps and whistles. For example, in an optical apparatus such as an interferometer, noise may be intercepted by the optical bench and transferred to the interferometer where it changes the scan mirror speed, thus interfering with the gathering of information.
Rubber mounts are used typically for vibration isolators, but conventional rubber mounting systems allow too much freedom of movement to dampen vibrations and maintain optical alignment. Holding a rubber isolator such as an isolator ring in horizontal compression reduces such freedom of movement. However, rubber acts as an incompressible fluid and, therefore, thickens under such compression. Such thickening is somewhat uncontrollable and results in uneven heights of the several mounts required for support, thus tilting the apparatus.
A further problem is misalignment evolving from the normal tolerances of fabrication of the support bench and the carriage for the apparatus. Conventional slots for mounting pins can allow for adapting to variations within broad tolerances. However, even conventional cylindrical rubber pins forced into slots in compression may not sufficiently resist vibrational motion.